Assertion and reason

Exercise and reference answers

Questions

1. Reason

   The rate law is an experimental result, not a stoichiometric one.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   A rate law cannot be written from the balanced equation alone.

2. Reason

   It lowers the activation energy by opening an alternate path.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   A catalyst speeds a reaction up.

3. Reason

   Order is found experimentally and may be fractional.

   Verdict

   The assertion is false and the reason is true.

   Assertion

   Molecularity can be a fraction.

4. Reason

   In k = Ae^(−Ea/RT), a larger T makes the exponent less negative.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Raising the temperature raises the rate constant.

Explanation